Featured Research

Measuring The Muscle: New Study By Scripps Researchers Depicts How The Tuna’s Body Is Built For Speed

Date:

April 18, 2001

Source:

Scripps Institution Of Oceanography

Summary:

The mechanics of how fish use their complex muscle systems is a tantalizing puzzle in animal physiology. These muscles are the fundamental sources that fish use to power steady swimming and bursts of speed to elude predators and to capture prey. Scientists have long predicted that tuna, with their highly streamlined body and elevated internal temperatures, are equipped with a "high performance" muscle system. Tuna, researchers suspected, power their swimming by projecting muscle force from the mid-body, where the muscle is concentrated, back to the tail, which essentially acts as a natural, thrust-producing hydrofoil.

Share This

The mechanics of how fish use their complex muscle systems is a tantalizing puzzle in animal physiology. These muscles are the fundamental sources that fish use to power steady swimming and bursts of speed to elude predators and to capture prey. Scientists have long predicted that tuna, with their highly streamlined body and elevated internal temperatures, are equipped with a "high performance" muscle system. Tuna, researchers suspected, power their swimming by projecting muscle force from the mid-body, where the muscle is concentrated, back to the tail, which essentially acts as a natural, thrust-producing hydrofoil.

Related Articles

Now, through a study sponsored by the National Science Foundation and conducted at Scripps Institution of Oceanography at the University of California, San Diego, and the National Marine Fisheries Laboratory in Honolulu, researchers have for the first time documented this muscle action in motion. Stephen Katz, Douglas Syme, and Robert Shadwick report their results in the April 12 edition of the journal Nature.

"The anatomy has been known for a long time, especially the idea that the connective tissue architecture in tunas allows muscles to focus their action further down the body," said Shadwick, a professor in Scripps’s Marine Biology Research Division. "We’ve taken measurements directly from swimming fish to show it working this way."

In other fishes, such as trout and mackerel, swimming muscles are distributed more uniformly along the body. When their muscles shorten and produce power, the burst is seen as a wave of contraction that causes the entire body to undulate.

Tuna, however, contain swimming muscles located primarily in the central part of the body. Tendons that angle to the backbone link the muscle with the tail.

Using ultrasound technology, Shadwick and his colleagues attached tiny transducers directly to tuna muscles to record the muscle electrical activity and contraction as tuna swam in a large water tunnel. A device called a sonomicrometer measured the muscle shortening by timing the ultrasound signal between pairs of transducers.

"When we went inside the fish with ultrasound, we saw that the muscle contraction caused bending to occur further down the body," said Shadwick. "We now know that because the muscle tunas use for cruising is close to the backbone–not adjacent to the skin as in other fish–it is allowed to do large amounts of shortening, which means more work and more power production. That’s the essence of how this fish is different from others. Hydrodynamically, that’s a more effective way to swim. If all the middle segments throughout the body were undulating, it would create much more drag. Tunas have a more streamlined body and the motion at the tail acts almost like a propeller."

Shadwick says the results of the study hold implications for research in comparative physiology and the evolutionary biology of fishes. The results also could be important for the design of robotic, self-propelled autonomous underwater vehicles that mimic biological design.

The results have prompted Shadwick to move to other species. With new support from the National Science Foundation, he and Scripps researcher Jeffrey Graham have launched a new study to search for the same results in lamnid sharks.

Scripps Institution Of Oceanography. "Measuring The Muscle: New Study By Scripps Researchers Depicts How The Tuna’s Body Is Built For Speed." ScienceDaily. ScienceDaily, 18 April 2001. <www.sciencedaily.com/releases/2001/04/010415222617.htm>.

Scripps Institution Of Oceanography. (2001, April 18). Measuring The Muscle: New Study By Scripps Researchers Depicts How The Tuna’s Body Is Built For Speed. ScienceDaily. Retrieved March 3, 2015 from www.sciencedaily.com/releases/2001/04/010415222617.htm

Scripps Institution Of Oceanography. "Measuring The Muscle: New Study By Scripps Researchers Depicts How The Tuna’s Body Is Built For Speed." ScienceDaily. www.sciencedaily.com/releases/2001/04/010415222617.htm (accessed March 3, 2015).

More From ScienceDaily

More Plants & Animals News

Featured Research

Mar. 3, 2015 — New assays can detect malaria parasites in human blood at very low levels and might be helpful in the campaign to eradicate malaria, reports a new study. An international team led by Ingrid Felger, ... full story

Mar. 3, 2015 — While studying a ground-nesting bird population near El Reno, Okla., a research team found that stress during a severe weather outbreak of May 31, 2013, had manifested itself into malformations in ... full story

Mar. 3, 2015 — The 3-D printing scene, a growing favorite of do-it-yourselfers, has spread to the study of plasma physics. With a series of experiments, researchers have found that 3-D printers can be an important ... full story

Mar. 3, 2015 — Most people consume more salt than they need and therefore have a higher risk of heart disease and stroke, which are the two leading causes of death worldwide. But a new study reveals that dietary ... full story

Mar. 3, 2015 — By examining the forces that the segments of mosquito legs generate against a water surface, researchers have unraveled the mechanical logic that allows the mosquitoes to walk on water, which may ... full story

Mar. 3, 2015 — Pediatric otolaryngologists and surgeons are concerned with parents getting the wrong message regarding the safety/desirability of letting babies and young children eat peanuts to prevent them from ... full story

Mar. 3, 2015 — Researchers have developed a new way of rapidly screening yeasts that could help produce more sustainable biofuels. The new technique could also be a boon in the search for new ways of deriving ... full story

Mar. 3, 2015 — Similar to humans and animals, plants possess an innate immune system that protects them from invading pathogens. Molecular structures that only occur in pathogens enable their recognition and ... full story

Mar. 3, 2015 — For almost a century, scientists have been puzzled by a process that is crucial to much of the life in Earth's oceans: Why does calcium carbonate, the tough material of seashells and corals, ... full story

Featured Videos

Rare Goblin Shark Found in Australia

AFP (Mar. 3, 2015) — A goblin shark, a rare sea creature described as an &apos;alien of the deep&apos; is found off Australia and delivered to the Australian Museum in Sydney. Duration: 01:25
Video provided by AFP

Zookeepers Copy Animal Poses In Hilarious Viral Photos

Buzz60 (Mar. 2, 2015) — Zookeepers at the Symbio Wildlife Park in Helensburgh, Australia decided to take some of their favorite animal photos and recreate them by posing just like the animals. Jen Markham (@jenmarkham) has the story.
Video provided by Buzz60

Related Stories

Feb. 5, 2015 — Scientists have discovered how prized bluefin tuna keep their hearts pumping during temperature changes that would stop a human heart. The research helps to answer important questions about how ... full story

Oct. 7, 2013 — Snake and eel bodies are elongated, slender and flexible in all three dimensions. This striking body plan has evolved many times independently in the more than 500 million years of vertebrate animals ... full story

Oct. 14, 2011 — A meat-eating dinosaur that terrorized its plant-eating neighbors in South America was a lot deadlier than first thought, a researcher has found. Carnotaurus was a seven-meter-long predator with a ... full story

Oct. 7, 2011 — Two new studies have shown that the coexistence of tuna larvae of different species and sizes in the spawning areas is essential for the survival of such early life stages, since cannibalism can ... full story

Mar. 10, 2010 — A 10-year effort by a scientist to develop transgenic rainbow trout with enhanced muscle growth has yielded fish with what have been described as six-pack abs and muscular shoulders that could ... full story

ScienceDaily features breaking news and videos about the latest discoveries in health, technology, the environment, and more -- from major news services and leading universities, scientific journals, and research organizations.